Conventionally, a fuel feed apparatus includes a sub-tank accommodated in a fuel tank. The fuel feed apparatus further includes a jet pump for supplying fuel from the fuel tank into the sub-tank. Specifically, according to US 2004/0074995 A1 (JP-A-2004-156588), a jet pump supplies fuel into the sub-tank, so that the fuel level in the sub-tank can be maintained higher than the fuel level in the fuel tank, even when fuel in the fuel tank decreases. In this structure, the fuel pump accommodated in the sub-tank is capable of steadily pumping fuel from the sub-tank, even the fuel level decreases in the fuel tank.
In US 2004/0074995 A1, a jet pump is welded to the outer wall surface of the bottom portion of the sub-tank. When the jet pump is welded to the sub-tank, the jut pump may be applied with force onto the sub-tank.
Here, a jet pump is capable of generating a swirl flow to jet the swirl-flowing fuel through a jet nozzle. In this jet pump, a swirl chamber is provided in upstream of the jet nozzle for supplying swirl-flowing fuel toward the jet nozzle. In general, a cylindrical member defines the swirl chamber therein.
When the cylindrical member defining the swirl chamber is applied with force toward the sub-tank, it is difficult to steadily applying force onto the round surface of the swirl chamber. Therefore, when application of force to the cylindrical member is unstable, the cylindrical member may be tilted, and misaligned with respect to the sub-tank.
Furthermore, when the cylindrical member defining the swirl chamber is directly applied with force, the cylindrical member may be deformed, and the shape of the swirl chamber cannot be maintained.